Hearing protection devices, such as earplugs, are readily used to provide sound attenuation. Earplugs include any of a variety of devices designed to be inserted in the ear canal of a user and worn therein to prevent sounds from entering. Generally, there are two types of earplugs: push-in earplugs and roll-down earplugs.
Push-in type earplugs generally comprise an attenuating portion and a rigid or semi-rigid portion typically extending therefrom or embedded therein. The sound attenuating portion is typically of a soft compressible material; the rigid or semi-rigid portion may be composed of any material, such as a plastic or a rubber, with sufficient rigidity as required.
To insert the push-in type earplug, the user grasps the rigid/semi-rigid portion (or an end of the earplug proximate thereto), positions the earplug proximate the ear canal opening, and inserts the sound attenuating portion into the canal by pushing with the rigid/semi-rigid portion. The sound attenuating portion compresses, as necessary, upon entry into the ear canal and is held therein by a friction fit, occluding the canal and providing sound attenuation. Such a push-in type earplug may be found, for example, in U.S. Pat. Nos. 4,867,149 and 5,188,123 to Falco and Gardner Jr., respectively, which are herein incorporated by reference in their entirety.
These known push-in type earplugs have been found to be effective at attenuating sound and thus providing sufficient hearing protection to the wearer. For example, such earplugs, when properly inserted have been shown to provide a Single Number Rating (hereinafter, “SNR”) often greater than 25. However, sometimes a relatively lower level of sound attenuation is desired. For example, an earplug wearer in a low-noise environment may desire an SNR of approximately 20 or lower. Such reduced SNR would provide the wearer with sufficient attenuation while allowing certain sounds, such as nearby conversation, to penetrate the ear. The push-in earplug would likely provide to much attenuation to allow such desirable sounds to be audible. Also, certain discomforts are typically associated with this type of push-in earplug as a result of the presence of the rigid or semi-rigid stem portion. Further, manufacture of the push-in earplug may be complicated and relatively expensive in that the attenuating portion and the rigid or semi-rigid portion may be required to be formed separately and then later affixed together.
A roll-down type earplug includes an attenuating portion similar to that of the push-in but does not include the rigid or semi-rigid portion. Instead, insertion is facilitated by rolling down the earplug into a compressed state having a reduced diameter which enables the earplug to be passed into the earcanal wherein the earplug expands to occlude the canal. A typical roll-down earplug may be found in U.S. Pat. No. 6,105,715 to Knauer which is herein incorporated by reference in its entirety.
As with push-in type earplugs, roll-down plugs attenuate sound by causing an occlusion deep within the earcanal, thus obstructing the passage of sound therethrough. However, the required insertion method is slightly more complex, requiring a precise roll-down of the plug and a manipulation of the pinna portion of the ear during ear canal insertion. See, U.S. patent application Ser. No. 10/740,180 filed on Dec. 17, 2003, which is herein incorporated by reference in its entirety.
Errors during insertion of roll-down earplugs result in improper fit within the earcanal, and thus full occlusion may not be achieved. For example, the earplug may be rolled down properly, but only inserted partially into the earcanal. Thus, the surface area of the plug in contact with the earcanal walls is reduced, full occlusion is not attained, and attenuation is degraded. Further, the earplug may be mis-handled during pre-insertion roll-down preparations. For example, the plug may improperly rolled and/or compressed prior to insertion such that creases are formed on the surface of the plug. These creases act as sound channels and permit the leakage of sound into the canal, thus degrading occlusion, and effecting attenuation.
These roll-down earplugs provide a degree of comfort to the wearer but are often regarded as complicated to properly insert into the ear canal. Additionally, once inserted, such roll-down earplugs typically provide a high SNR (e.g., 30 or higher). Thus, these roll-down earplugs may not be effective in a low noise situation where a reduced SNR is desired.
Partial insertion of either the push-in type or roll-down type earplugs may provide a lesser SNR than such earplugs provide when fully and properly inserted. However, it would be extremely difficult to attain a consistent reduced SNR in this manner because the slightest deviation in partially inserting one earplug over another would increase or decrease the attenuation provided thereby. Moreover, there is no way that a user could accurately know the protection provided by a partially inserted traditional push-in or roll-down earplug. Thus, in attempting such partial insertion a wearer may inadvertently reduce the SNR far too much thus exposing the inner ear to damaging noise.
Accordingly, an earplug is desired which is inserted simply and effectively, and which is comfortable to the wearer, and which provides a consistent relatively lower sound attenuation than traditional push-in and roll-down earplugs.